Question

Petrification occurs when _____.
shell, bone, or wood is replaced with dissolved minerals
dead organisms are exposed to oxygen and calcium carbonate
a cast fossil is later filled with minerals
an organism is completely preserved in ice or oil

Answer 1

Petrification happens when substances or objects get replaced with mineral molecules, so that would be the first answer; shell bone or wood is replaced with dissolved minerals.

Answer 2

Answer: Option A  

Explanation:  

Petrification can be defined as the biological phenomenon in which the organic materials like shell, bones and plants becomes a fossil by replacing the the original organic material and filling of the original space by minerals.  

All the living organism undergoes this process. The dead and decaying organism dies and then petrifies to form fossil.

Hence, the correct answer is option A